Accessible twin-lever gear shift for drill heads



D. c. KLAUsMEYl-:R

Filed sept. 18, 1924 'Dea 25, 1928.

ACcEssIBLE' TWIN LEVER GEAR. SHI-FT FOR Dimmil `HEADS Patented Dec. 25, 1928.

UNITED STATES;PTENT'O-FFICVE.

DAVID C. KLAUSMEYER, OF CINCINNATI, OHIO, ASSIGNOR THE CICINNATI: BIOK4 FORD TOOL COMPANY, OF OAKLEY,` CINCI'NAII,` OHIO, yA CORPORATION OF 10H10.

Aocnssinnn TWIN-LEVER sans SHIFT non :Darrin Hanns. n

Application 'filed September 18, 1924. Serial No. 738,440.

This invention relates to radial drilling machines and more particularly to means for selectively meshing certain speed-change gears which of necessity are located in an inaccessible position in the drill-head.

Radial drills, as commonly constructed,`

comprise a base, an upright column9 anda laterally projecting arm upon whichl is slidingly mounted a drill-head carryinga vertically disposed drill-spindle. Power to rotate the drill-spindle and feed it vertically may be provided by a motor or other primenioverlocated on the base at the foot. of the column, and the povver therefrom may be transmitted through suitable mechanism to a shaft journaled lengthwise of the radial arm and thence tl'iiough suitable change,- gearrmechanisms to the drill-spindle.

As vis Well understood by those skilled in the art, it is essential that means be provided for regulating the speed of rotation of the drill-spindle inasmuch as the varying diameters of the drills and taps .beingused and the nature of the Work being operated on, each present Working conditions Which require different speedsof rotation of the spindle to produce maximum efficiency in operation.

To provide these various speeds itfhas heretofore been customary to locate adjacent the prime-mover7 a change-gear' mechanism capable of transmitting` about sin or eight different speeds from a single speed received from the prime-mover. The differences in ratio afforded by this so-called speed-box control are necessarily small since there is considerable mechanism actuated thereby and great" differences in ratio would effect abrupt changes and cause strains that would he detrimental to the parts.

Coarser changes are provided by a changegear mechanism located in the drill-head. These latter change-gears are commonly known as the back-gears and usually provide four speed changes which multiply the number of speeds provided by thespeed-box. Inas'niuch as only thespindle is actuated by. the ,back-gears the speed changes provided therein may be materially greater than Vthose provided in the speed-boX.

The back-gears .are preferablylocated in the upper end of the drillhe`ad,rintermediate the horizontal arm shaft and the upper end of the spindle and comprise a plurality of fixed and shiftable gear-units. Inasniuch as these gears are expensive to manufacture and furthermore as in operation they attain means therefor Which islocated adjacent the gears is also out of the operator"s` reach Which necessitates the use ofy a ladder,` bonA or the like to enable him to reach the rearsliiftersthereby'toinake the necessary lspeed changes.v

`Various devices have heretofore been 'provided for the shifting of these back-gears `but they are all more or less inconvenient or inaccessible and none is yentirely `satisfactory. It is believed that the most/nearly satisfactory device heretofore provided is that disclosed in applicants Patent Non lOfloSof which the present invention is an improvement. Applicants prior con struction,r however, has its shortcomings inasmuch as it admits of only tlii'ee speed- 'changes and ldue to the nature of the shift` ing mechanism requires eight gears and four clutches to produce the three speed-changes.

This invention 'has for an object to pro-v vide iniiiroved means,` conveniently accessible to the'opcrator, for shifting' the backg'ears in a radial-drill head. d

A "further object of the invention istok provide anf improved back-gear shifting` mechanism conveniently accessible t0 the 0p-l erator andvvhich isso constructed' and arrangedl that at least four speed changes may be eifected with a minimum number of gears: n A v fA still further o-bjectof this invention is to provide, in connection 'with tivo shiftable gear-units of radial drill back-gears, independent shiftiiig' devices for saidgear-units, each ldevice having its own controllinglelements, said controlling elements beingg'llo-y cated easily accessible `to the operator and having an operative connection v'vith theremote and inaccessible gear-units.

lli

Other obje-cts and advantages will be in part indicated in the following description and in part rendered apparent therefrom in connection with the annexed drawings.

To enable others skilled in the art so fully to apprehend the underlying features hereof that they may embody the same in the various wa-vs contemplated by this invention, drawings depicting a preferred typical construction have been annexed as a part of this disclosure and, in such drawings, like characters of reference Vdenote corresponding parts throughout all the views, of which F ig. 1 is a vertical section of a drill-head embodying the present invention. Fig. 2 is ahorizontal section on the line 2 2 of Fig. 1. Fig. 3 is a detail section substantially on the line of Fig. 2. Fig. 4 a det-ail front view of a portion of the drill-head showing the gear-shifting arms carried thereby and the rack-bars actuated by the arms. Fig. 5 is a section on the line 5 5 of Fig. 4.

Referring more particularly to the drawings the invention is disclosed as embodied in a drill-head indicated generally as l. This drill-head is formed with guide-ways 2 and 3 adapted to slide upon a suitable radialarm, (not shown) as is common to this type of machine-tool. A variable speed-shaft 4 is journaled lengthwise of the arm and carries two bevel-gears one only, of which is shown.

These gears are adapted to drive, in oppositek directions, a similar bevel-gear 5 fixed upon a vertical shaft 6 journaled in the drill-head. lnasmuch as the means for rotating the shaft 4 at varying speeds and the means for reversing the direction of rotation of the shaft 6 form no part of this invention detail illustration and description thereof is deemed unnecessary. Y

Slidably secured to the shaft 6, as by means of splines 7, is a gear-unit 8 provided with gears 9 and 10. These gears are adapted selectively to be brought into mesh with gears 11 and 12 provided by a nonlranslatable gear-member 13 secured upon an intermediate shaft 14 journaled in bearings c and l in the drill-head. The gearmembe1113 may be formed as a unit or, for convenience of manufacture, it may be made in separate pieces a and o as shown in Fig. 1. vThe shaft 14 also carries a small gear 15 and the gear-member 13 provides a gear 16, both later to be referred to.

Rotatably journaled in the drill-head 1 is a sleeve 17 within which is splined, for vertical movement, the usual drill spindle 18 adapted to carry at its lower end a drill 19, or other suitable tool. Thus rotation of the sleeve 17 will, through the spline connection 20, likewise effect rotation of the spindle 18 and still permit the spindle to be moved vertically in the sleeve.

VTo the sleeve 17 is slidably secured,'as by means of splines e and f a gear-unit 21. rl`his gear-unit provides'a gear 22, adapted upon one movement of the unit to be engaged with the gear 1G and a series of clutchteeth 23v adapted in another movement of the unit to engage similar clutch-teeth 24 formed in a gear-member 25 loosely journaled coaxial with the sleeve 17.

The member 25 is also formed with a gear 2G maintained permanently in mesh with the gear 15. From the foregoing it will be seen that by selectively meshing the gears 9 and 11 or 10 and 12 any given speed of the shaft G may be converted into two speeds in the shaft 14. Likewise each of these two speeds may be converted into two different speeds in the spindle-driving sleeve; this last conversion being selectively effected by shifting the gear-unit 21 in one direction lengthwise ot the spindle to mesh the gears 1G and 22 or in the oppositefdirection to Cause power to flow from the shaft 14 through gears 15 and o 26 and clutch-teeth 23rand 24 to the drivingunit 21.

rlhe gear-units 8 and 21 may be shifted into either of their operative positions to effect the desired spindle speed by an improved means now to be described. Fnlcruined intermediate its ends upon a shaft 27, secured in the upper part ofthe. drill-head, is a lever 28 which carries at one end a fork 29 embracing the shiftable gear-unit 8. The opposite end of the lever 23r is formedpas gearsegment 30 which is engaged by the teeth 31 of an eridwise movable gear-shifting rod 32. A lever 33, of the second order, is also fulcrumed upon the shaft 27 and carries, intermediate its ends, a gear-shifting fork 34, engaging the gear-unit 21. The lever is also formed with a gear-segment 35 which meshes with the teeth 3G of a gear shifting rod V37,-similar to thevrod 32. The rods 32 and 3T extend downwardly from the segments 30 andv 35 beside the drill-head and are provided at their lowe; ends with rackteeth 32 and 37*l reslgiectively. lfVithiu ears g and Z1, provided by the lower portion of the drill-head, is journaled a short shaft 38, to which is secured, as by a pin 39, a gear 40. This gear is maintained pernninently in mesh with the teeth 37a, of the rod 37, and may be rotated to shift the rod vertically by means of a hand-lever 41 also secured to the shaft 38. A gear 42, similar to the gear 40, is loosely journaled upon the shaft 38 and permanently meshes with the teeth 32 of the rod 32. A hand-lever 43 is formed integral with the gear 42 and affords means for rotating the latter tti-effect vertical movement of the rod 32.

From the foregoingit will be seen that by manipulation of the levers 41 and 43 the rods 32 and 37 may be shifted vertically and that these rods, acting upon the levers 28 and 33 and the gear-shifting forks 29 and 34 lijn lll)

Will cause the gears 9 and l1, l0 and l2, 16 and 22 and clutch-elements 23 and 24E selectively to be engaged to effect any one of four available speed-changes in the drillspindle.

To maintain the teeth 3l and 36 in engagement with the segments 30 and 85 and to prevent lateral displacement of the rods 32 and 37, these rods are preferably guided at their upper ends by means of the Walls t, j and 7c of a stud 44 carried by a bracket Zi5 secured to the drill-head. The loiver ends may be similarly guided by abar i6 secured to the ears g and 7L.

It is to be understood that the. levers fil and 43 are carried at the lower end of the drill-head and therefore are easily accessible to the operator in all of the adjusted positions of the arm and drill-head.

rloprevent accidental shifting ojr' the levers 2S and 33 and the gear-units 8 and 2l the levers arev provided with sectors 28 and 33EL respectively. These lsectors are provided With indentations 28h and 33h adapted itccbe engaged by spring detents 28, and

`From the foregoing it Will'be seen that there has been provided an improved backgear mechanism comprising only eight gears that produce four speed-changes and also novel means readily accessible Vto the operator for shifting the gear-units.

Vithout further analysis, the foregoing will so fully reveal the gist of this invention that others can, by lapplyingV current knowledge, readily adapt it for various utilizations by rretaining one or more of the features that, from the standpoint of the prior art, fairly constitutev essential characteristics of either' the generic or' specific alspects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended Within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, I claim as nenr and Vdesire to secure the follow-- ing combinations and elements, or equivalents thereof, by Letter-'s Patent of the United States:

1. 1n a machine tool, in combination, a plurality of shiftable gear-units; a gearshifter engaging each of said gear-units;

gear-shifting levers of the first and second class, respectively, journaled coaxially in said machine tool between said gear units, each of said levers being formed integral with a gear-segment and each lever' Wholly supporting one of said gear Shifters; actuating hand-levers located remote from gearshifting levers; and operative connections between said hand levers and said gearshifting levers whereby the latter are actuated by the former, each of said connections including a rack-bar engaging the gearsegments on said gear-shifting levers and operative connections'between said actuating levers and said rack bars.

2. A gear-shifting mechanism. combining a plu 'ality of shiftable gear-units; a gear shifter engaging each of said gear units; gear-shifting levers fulcruined upon a common axis and each carrying` one of said gear-shifters; a gear-segment carried by each of said levers; a translatable rack-bar meshing with each of said gear segments; means to translate said rack-bars; and a stationary stud located at the side of said rods remote from said gear segments, said stud being formed with transverse Walls engaging transverse surface of (said rack-bars to maintain said rack-bars in Contact With said gear-segments and to prevent lateral movement of saidrack-bars.

3. In a drill-head, in combination, a driveshaft; a spindle; a change-speed mechanism operatively connecting said drive-shaft With said spindle and including two shiftable gear-units; two levers fulcrumed adjacent said change-speed mechanism and each connected with one of said shiftable gear-units, each of said levers being provided With a toothed sector' and a plain Vsector provided With an indentation; a rack-bar meshing with said toothed sector; means operable from a point remote from the change-speed mechanism for shifting said rack-bar to osmy name.

DAVID o. KLAUsMEYnR,

accidental movement 

